1. Field of the Invention
This invention relates to a method for producing very small size alumina spheroids utilizing air or some other immiscible fluid either in a gaseous or liquid form.
2. Description of the Previously Published Art
The Sanchez et al patent U.S. Pat. No. 4,179,408 discloses a method for forming alumina spheroids. An acidified alumina slurry is obtained with an alumina and this slurry is sent through dripping nozzles where the alumina slurry forms a droplet at the end of the nozzle. As the droplet grows large, it reaches a diameter on the order of 4-7 mm. at which point its weight causes it to fall from the nozzle. It then passes through air and into an ammoniated kerosene-containing column. As the droplet passes through this column it is formed into a spheroidal particle and hardens.
The particles obtained by this technique are of a generally large size having diameters of about 3 mm. or larger after they have been calcined.
3. Objects of the Invention
It is an object of this invention in one embodiment to use the basic alumina spheroid production technique disclosed in the Sanchez et al U.S. Pat. No. 4,179,408 and to make smaller size particles in a controlled manner where the diameter can be controlled to form particles which after being calcined have diameters from about 0.05 mm. to about 3.0 mm.
It is a further object of this invention to produce small size alumina spheroids with good crush strength and good attrition resistance.
It is a further object to produce not only small size particles, but to increase the number of droplets per unit time so as to increase the volume throughput.
It is a further object to produce small alumina spheroids suitable for catalyst support use having diameters of about 3 mm. or less.
It is a further object to have an effective spray dry process to produce spheroidal alumina particles which after being calcined have a controlled size within the diameter range of about 0.01 mm. to about 0.40 mm.
These and further objects of the invention will become apparent as the description of the invention proceeds.